Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS4512681 A
Publication typeGrant
Application numberUS 06/288,754
Publication dateApr 23, 1985
Filing dateJul 31, 1981
Priority dateAug 5, 1980
Fee statusPaid
Also published asCA1156849A1, DE3161787D1, EP0045624A1, EP0045624B1, EP0045624B2
Publication number06288754, 288754, US 4512681 A, US 4512681A, US-A-4512681, US4512681 A, US4512681A
InventorsGordon A. Hayhurst, David A. Rayner
Original AssigneeJ.H. Fenner & Co. Limited
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
For securing pulleys
US 4512681 A
Abstract
The present specification discloses a tapered, longitudinally-split contractible taper bush for securing pulleys, sprockets, coupling flanges or other machine elements onto cylindrical shafts and utilizing a plurality of screws or bolts parallel with the hub axis for effecting wedging of the bush between the hub of the element and the shaft onto which it is mounted. Known bushes of this type suffer an out of balance moment due to the arrangemnt of locking holes, part threaded holes provided for de-wedging and bush removal, and the size of the longitudinally extending slit which is necessary to promote flexibility in the bush for bush removal.
The present invention overcomes the out of balance problem by providing profiling in the region of the longitudinal slit so that the disposition of metal is then such as to compensate for the mass imbalance in both the bush and a co-operating mating hub, a rotationally balanced system being thus provided.
Images(1)
Previous page
Next page
Claims(14)
We claim:
1. In a tapered, longitudinally-split contractable taper bush for securing pulleys, sprockets, coupling flanges or other machine elements onto cylindrical shafts and wherein the bush has a central axis and three holes extending axially of the bush at angularly spaced locations about said axis for receiving screws or bolts parallel to said axis for wedging the bush between the element to be secured and a shaft positioned axially within the bush and wherein the bush has a longitudinal slit extending throughout the axial length of the bush at a location between two of the holes opposite the third hole in the bush, the improvement comprising an enlargement of the longitidunal slit wherein the enlargement is of predetermined size and distance from said axis to impart substantial rotational balance to the bush and the element and shaft to be associated therewith during use thereof.
2. The bush defined in claim 1 wherein said bush includes opposite surfaces defining said slit and an axis of symmetry extending between said surfaces, and wherein said enlargement is symmetrically positioned on opposite sides of said axis of symmetry of the slit.
3. The bush defined in claim 2 wherein said enlargement includes a recess opening into said slit.
4. The bush defined in claim 3 wherein said recess extends throughout the length of the bushing.
5. The bush defined in claim 4 wherein said recess has a constant cross-section axially of the bush throughout the length of the bush.
6. The bush defined in claim 5 further including an outer surface and wherein said recess opens into said outer surface of the bush on opposite sides of said slit.
7. The bush defined in claim 6 having flat surfaces defining said recess.
8. The bush defined in claim 6 having arcuate surfaces defining said recess.
9. The bush defined in claim 1 wherein said bush has an outer surface and recessed surfaces extending between said outer surface and slit to define said enlargement.
10. The bush defined in claim 9 wherein said recessed surfaces extend axially of the bush throughout the length thereof.
11. The bush defined in claim 10 wherein said slit has an axis of symmetry and said recessed surfaces are symmetrically positioned relative to said axis of symmetry on opposite sides of said slit.
12. The bush defined in claim 11 wherein said recessed surfaces are substantially planar surfaces.
13. The bush defined in claim 11 wherein said recessed surfaces are curved surfaces.
14. In a bush and hub assembly for securing pulleys, sprockets, coupling flanges or other machine elements onto cylindrical shafts, the assembly including a hub, a taper bush received in the hub and having a central axis and three holes extending axially of the bush at angularly spaced locations about said axis, fasteners such as screws or bolts received in said holes generally parallel to said axis for wedging the bush between the hub and a shaft to be positioned axially within the bush, and wherein the bush has a longitudinal slit extending between two of the holes opposite the third hole in the bush, the improvement comprising an enlargement of the longitudinal slit wherein the enlargement is of predetermined size and distance from said axis to impart substantial rotational balance to the bush and the hub and the shaft to be associated therewith during use thereof.
Description
DESCRIPTION

This invention relates to taper bushes designed for hub and bush assemblies for securing pulleys, sprockets, coupling flanges or other machine elements to cylindrical shafts.

More specifically the invention is applicable to tapered, longitudinally-split, contractible bushes of the type disclosed in British Patent Specification No. 592,912.

In certain types of known taper bush system which utilise a plurality of screws or bolts parallel with the hub axis to produce a wedging effect of the bush between the hub of a pulley or other element and a shaft, the symmetrical configuration of the bush is distorted by the disposition of metal removal designed to facilitate securement of the bush and element onto the shaft and also to provide for subsequent and ready removal of these elements from the shaft. The hub into which the bush fits is often similarly asymmetrical, being provided with three holes located to match those in the bush. This lack of symmetry in the system inevitably affects the balance of the bush and hub assembly which can lead to excessive vibration during rotation. This is especially disadvantageous when the assembly is located in vibration-sensitive situations particularly on relatively flexible structures.

In operation of course, locking holes are normally partially filled by locking screws, or bolts, the mass of which can be taken into account. A keyway is sometimes employed which is machined in the parallel bore of the bush to mate with a similar keyway in the shaft. In this case, where a key of similar material and axial length to the bush is employed, the effect on the balance of the system can be minimised by arranging for the respective keyways in the shaft and bush to be diametrically opposed.

With known types of bushes, the resultant assembly may still suffer an out of balance moment due to part of the locking holes, the part-threaded hole provided for de-wedging and bush removal, and the size of slit which is necessary to promote compliance of relatively massive bushes.

One object of the present invention is to provide a bush which overcomes or at least mitigates these difficulties and disadvantages resulting from the out of balance moment present in the complete assembly comprising bush and mating hub.

According to the present invention, a tapered, longitudinally-split contractible taper bush for securing pulleys, sprockets, coupling flanges or other machine elements onto cylindrical shafts and utilising a plurality of screws or bolts parallel with the hub axis for effecting wedging of the bush between the hub of the element and the shaft onto which it is mounted, is profiled in the region of its longitudinal slit so that the disposition of metal is such as to compensate for the mass imbalance in both the bush and a cooperating mating hub and thus provide a rotationally balanced system.

The profiling is dimensioned and contoured so that it may be cheaply and conveniently carried out on high volume multi-operation machinery, although bushes according to the invention may equally well be produced by sintering, casting, or other forming processes.

Preferably, the profiling comprises a widened longitudinal slit or it may be a shallow or local enlargement symmetrically positioned about the longitudinal slit.

In a particularly preferred embodiment, the shaping comprises a hole drilled partially and longitudinally in the region of the slit.

Generally, material removal to effect balance is by machining of an aperture of constant section in the axial plane. Consideration of the dynamic balance of the system requires removal of material over the full length of the bush for optimum effect.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows a conventional bushing of the prior art type described in elevation;

FIG. 2 is an angled section taken along the line II--II of FIG. 1; and

FIGS. 3, 4 and 5 show schematic end elevations of the three different embodiments of the present invention.

Considering the bushing of FIGS. 1 and 2, and looking axially on the end elevation, it is apparent that the sum of the volumes of metal removed from the otherwise solid assembly i.e. bush A and hub B, is symmetrical about the plane y--y, but is asymmetrical about the plane x--x, thus creating a mass imbalance in operation.

FIG. 3 shows a bush 1 according to one embodiment of the invention whereby additional material has been removed from the bush 1 to form a widened longitudinal slit 3 and hence to create a state of balance when account is taken of all other metal removals 5,7,9, including those from the surrounding taper bored hub (not shown).

FIG. 4 shows another embodiment of the invention where the longitudinal slit 11 is widened locally as at 13 towards the outer surface 15 of the bush 17 sufficiently to create a state of balance again when account is taken of all metal removals.

FIG. 5 shows yet another embodiment of the invention in which the local widening 19 of the longitudinal slit 21 is achieved by drilling a hole partially within the bush 23.

Other embodiments are possible by suitably profiling the bush, conveniently in the region of the longitudinal slit which tends to become closed on cooperation of the bush with a surrounding mating hub.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1970435 *Jan 9, 1932Aug 14, 1934Baldwin Southwark CorpBalanced turbine or pump runner and method of balancing
US2140017 *Jul 15, 1938Dec 13, 1938Westinghouse Electric & Mfg CoFan construction
US2509711 *Nov 17, 1944May 30, 1950American Pulley CoMechanism for accomplishing axial shift of opposed surfaces of revolution; and also a process of making such mechanism
US2519958 *Nov 21, 1947Aug 22, 1950Dodge Mfg CorpWheel mounting
US2676849 *Aug 31, 1950Apr 27, 1954Deere Mfg CoAdjustable wheel assembly
US2714520 *Mar 6, 1952Aug 2, 1955Allis Chalmers Mfg CoFastening device for securing mechanical members to shafts or the like
US3074293 *Oct 15, 1959Jan 22, 1963Strong Scott Mfg CompanyBalancing device
US3085631 *May 29, 1959Apr 16, 1963Svenska Flaektfabriken AbPropeller fan blades
US3097824 *Nov 26, 1958Jul 16, 1963Bendix CorpTurbine, wheel containment
US3368833 *Jun 20, 1966Feb 13, 1968Dodge Mfg CorpHub and bushing structure
US3531216 *Dec 23, 1968Sep 29, 1970Allis Chalmers Mfg CoShaft attaching means for pump impeller
US3541882 *Dec 31, 1968Nov 24, 1970Perkin Elmer CorpElectrically insulating knobs
US3893779 *May 13, 1974Jul 8, 1975Buffalo Forge CoHub-to-shaft connection
US4140413 *May 27, 1977Feb 20, 1979Dynaloc CorporationHub-locking device
DE3011145A1 *Mar 22, 1980Oct 1, 1981Ralph MuellenbergSpannring
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4624597 *Aug 23, 1984Nov 25, 1986Reliance Electric CompanyFlanged bushing mounting adaptor
US4715243 *Aug 30, 1985Dec 29, 1987Mitsubishi Denki Kabushiki KaishaPlanetary reduction gear having a molded ring gear
US4996456 *Dec 1, 1989Feb 26, 1991Johnson Electric S.A.Axial retainers for coated electromagnetic rotor
US5205189 *Dec 17, 1990Apr 27, 1993General Electric CompanyEngine shaft balance assembly
US5280736 *Jan 11, 1993Jan 25, 1994General Electric CompanyEngine shaft balance assembly
US5367919 *Feb 24, 1993Nov 29, 1994Luk Lamellen Und Kupplungsbau GmbhCarrier for use in torque transmitting apparatus
US6053656 *Nov 20, 1997Apr 25, 2000Trw Occupant Restraint Systems GmbhFastener device for arresting a vehicle steering wheel to a steering shaft
US6568063 *Apr 6, 2000May 27, 2003Custom Machine & Tool Co., Inc.Concentric drive method and apparatus
US6616412Jun 20, 2002Sep 9, 2003Ingersoll-Rand CompanyTapered polygon coupling
US7670076Feb 26, 2008Mar 2, 2010Cnh America LlcMulti-sided shaft tapered locking hub apparatus
Classifications
U.S. Classification403/370, 403/371, 403/358, 73/66
International ClassificationF16D1/096, F16B3/06, F16B3/00, F16F15/32, F16D1/091, F16D1/09
Cooperative ClassificationF16D1/096, F16B3/00
European ClassificationF16D1/096, F16B3/00
Legal Events
DateCodeEventDescription
Aug 11, 1998ASAssignment
Owner name: FPT GROUP LIMITED, GREAT BRITAIN
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:J.H. FENNER & CO. LIMITED;REEL/FRAME:009375/0029
Effective date: 19980430
Sep 20, 1996FPAYFee payment
Year of fee payment: 12
Oct 5, 1992FPAYFee payment
Year of fee payment: 8
Oct 12, 1988FPAYFee payment
Year of fee payment: 4
Sep 21, 1981ASAssignment
Owner name: J.H. FENNER & CO. LIMITED, MARFLEET, HULL, NORTH H
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:HAYHURST, GORDON A.;RAYNER, DAVID A.;REEL/FRAME:003952/0241
Effective date: 19810721
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HAYHURST, GORDON A.;RAYNER, DAVID A.;REEL/FRAME:003952/0241
Owner name: J.H. FENNER & CO. LIMITED, A BRITISH COMPANY, ENGL